Remove IOThread::message_loop().

chrome/browser/process_singleton_linux.cc

Index: chrome/browser/process_singleton_linux.cc
diff --git a/chrome/browser/process_singleton_linux.cc b/chrome/browser/process_singleton_linux.cc
index cbf6492fa22cd9caec07f2be5101d81734ab2d48..34feef1901f0b0eff0edd7ed1d4b2c606564e96b 100644
--- a/chrome/browser/process_singleton_linux.cc
+++ b/chrome/browser/process_singleton_linux.cc
@@ -995,15 +995,13 @@ bool ProcessSingleton::Create() {
   if (listen(sock, 5) < 0)
     NOTREACHED() << "listen failed: " << safe_strerror(errno);
 
-  // Normally we would use BrowserThread, but the IO thread hasn't started yet.
-  // Using g_browser_process, we start the thread so we can listen on the
-  // socket.
-  MessageLoop* ml = g_browser_process->io_thread()->message_loop();
-  DCHECK(ml);
-  ml->PostTask(FROM_HERE, base::Bind(
-    &ProcessSingleton::LinuxWatcher::StartListening,
-    watcher_.get(),
-    sock));
+  DCHECK(BrowserThread::IsMessageLoopValid(BrowserThread::IO));
+  BrowserThread::PostTask(
+      BrowserThread::IO,
+      FROM_HERE,
+      base::Bind(&ProcessSingleton::LinuxWatcher::StartListening,
+                 watcher_.get(),
+                 sock));
 
   return true;
 }